This is just a quick reminder on the make up of a URL and basic details of a HTTP request/response cycle.

##URL

The following Uniform Resource Locator (URL), http://www.example.com/new, can be split into 3 parts

  1. http - The URL scheme

  2. www.example.com - the resource path or host

  3. /new - URL path

Additionally URL’s contain a port number which the host uses to listen to HTTP requests eg. http://www.example.com:80/new. The port is not always specified and port 80 will be used by default in normal HTTP requests.

##HTTP

####Request

  • Verb/Method: GET, POST

  • URL

  • parameters

####Response

  • Status code
    • 200 OK
    • 302 Redirect
    • 404 File not found
    • 500 Application error
  • payload/body
    • HTML, XML, JSON, etc

Remember that the request/response is stateless, ie requests are not connected.

For example

GET /page_with_form_on_it

  • render a view: 200 and an HTML payload (completes the response).
  • form is displayed for the user to enter data.

POST /page_with_form_on_it

  • save the data somewhere, say a database.
  • display the next thing. Redirect to another URL: 302 and next URL (completes the response). May also render again if there are errors on the form.

GET /the_next_thing

That’s it just a quick blog post as a reminder of some of the basics.